Cassavais one of the most versatile plants in the world and the fourth most important source of calories for the world’s population after rice, sugar and corn. Let’s start a series of articles to learn more about this plant.
Yuca (Manihot sculenta Crantz)
- Origin and distribution of the anduca
- Taxonomy of the anduca
- Morphological description of the anduca
Origin and distribution of cassava
is a plant whose origin is centered in the tropical and subtropical countries of the American continent and more specifically in the Amazonian territories. It is one of the most widespread crops in the world, although its commercialization on a global scale is very small since its production is limited to the self-consumption of the producing countries. The origin of this plant is in the northern part of South America and in the area between Mexico and Central America. The plant of the anduca is divided into two large groups:
- The sweet varieties, whose consumption is concentrated in the area between the north of Central America and the slope of Mexico that overlooks the Pacific Ocean.
- The amar g as varietiesconcentrated in the area between Paraguay and Northwestern Brazil.
There are data on cassava consumption as early as 2,700 BC. and in some tropical areas of Central America its cultivation and consumption begins even earlier than that of maize.
From America, cassava travels to the African continent by the hand of Portuguese navigators and from there to the Islands of the Pacific and the East.
Today 50% of the cultivated hectares of cassava are in Africa, 30% in Asia and the remaining 20% in Latin America.
Taxonomy of the anduca
Species: Manihot esculenta Crantz
The genus Manihot is formed by around 180 plants of good size whose main characteristic is the great development of its laticiferous vessels; the laticiferous vessels are the structures responsible for the segregation of latex and are present in various families of plants, such as Euphorbiaceae, Cannabaceae, Urticaceae, Moraceae, etc. and they are made up of a specialized type of cells called galactocytes that excrete a milky secretion. The secretion is intracellular and can be composed of carbohydrates, organic acids, mineral salts, alkaloids, lipids, tannins, mucilages, gums, proteins, vitamins, starch grains, crystals, etc.
Morphological description of
cassava As in any other animal or plant species, the environment in which a certain species develops has a final influence on its morphology. In the case of cassava it can be found from sea level to 1,800 meters of altitude hence the remarkable morphological and physiological diversification of the multiple varieties of cassava.
Cassava is a perennial, woody shrub with a short photoperiod and the height of the plantscan range from 5 meters to 5 meters, although they usually do not exceed 2.5-3 meters in height. It is monoecious (in the same plant the two sexes occur in different flowers) and of sympodial branching.
The stemis cylindrical and consists of a succession of knots and internodes, presenting a characteristic protrusion in the latter. Thedistance between two consecutive knots depends on the medium in which it develops; inthe knot the petiole of the leaf, an axillary bud protected by a scale and two lateral stipules are inserted. It consists of an outer bark, an inner bark and the central cylinder and its color can be yellow, light green, dark green, brown or reddish; its thickness is related to the production of the variety. Its diameter can range from 2 to 6 cm and as it thickens its degree of lignification increases. As we will see later, it is very important in the production of cassava plant for cultivation since they serve as cuttings to reproduce it asexually and from each cutting can come a stem or several, which branch at a certain height in several branches up to four floors, being the variety of three branches on the first floor the most cultivated. These branches can be fruiting or vegetative and it is the latter that will determine the final architecture of the plant.
Branched yucca stem
The leavesare simple, with a petiole of 10 to 20 cm and a webbed limb and with very deep lobes in number from 3 to 9, but always in odd number, the largest lobes being the central ones (very similar to the leaves of cannabis). The leaf bundle is covered by a bright waxy cuticle, while the underside is opaque and most of the stomata are located in it, although some varieties also have abundant stomata in the bundle. Depending on the variety they can be red or green or in reddish green tones. The leaves come off the knots as they age.
The rootThis is the organ of greatest economic value of the plant and its main characteristic is the ability it has to store starch, a complex and soluble carbohydrate formed by the union of glucose chains with linear structure (amylose) and branched glucose chains (amylopectin). Starch is mostly obtained from corn, wheat, rice, potato and cassava and si comes from a tuber is called starch and si is from a cereal simply starch.
The root system is not very thick but deep, being able to reach more than two meters deep, which gives the plant great resistance to drought. Thefirst stages are fibrous, but as the cycle progresses some branches (no more than 10) begin with their thickening; at this time the roots that will not thicken will continue to grow in length and those that thicken in width. The outermost part of the root is called the peridermis or “shell” and has a cork consistency. Below the peel is another layer called felodermis of less thickness and then the pulp, the usable part of the root, corresponding to more than 80% of the fresh weight of the root to the pulp.
Cassava root system
TheinflorescencesYucca is a plant with male and female unisexsual inflorescences on the same plant. They are of very simple structure and are grouped in clusters. Pollination is crossed and by insects since the female flowers open before the masculins, even being in the same cluster. The male flowers are smaller, yellowish, are found in greater numbers and occupy the distal end of the clusters; the female flowers are larger and purple in tones. The flowering of cassava is strongly influenced by climatology (floral induction).
The fruitThe fruit is a capsule with three carpels, provided with six wings, dehiscent and opened by six leaflets at maturity, which usually occurs from five months of pollination. The seed has an elliptical shape of 1-1.5 cm. in length, 6 mm in width and 4 mm in thickness.